   (.curveTightness *applet* (float ti)))
 
 (defn curve-vertex
+  "Specifies vertex coordinates for curves. This function may only be
+  used between begin-shape and end-shape and only when there is no
+  mode keyword specified to begin-hape. The first and last points in a
+  series of curve-vertex lines will be used to guide the beginning and
+  end of a the curve. A minimum of four points is required to draw a
+  tiny curve between the second and third points. Adding a fifth point
+  with curveVertex will draw the curve between the second, third, and
+  fourth points. The curveVertex function is an implementation of
+  Catmull-Rom splines."
   ([x y] (.curveVertex *applet* (float x) (float y)))
   ([x y z] (.curveVertex *applet* (float x) (float y) (float z))))
 

  (PApplet/radians (float degrees)))

(defn random
  ([max] (.random *applet* (float max)))
  ([min max] (.random *applet* (float min) (float max))))


  ([[r g b] [x y z] [nx ny nz] angle concentration]
     (.spotLight *applet* r g b x y z nx ny nz angle concentration)))

(defn sq
  "Squares a number (multiplies a number by itself). The result is
  always a positive number, as multiplying two negative numbers always
  yields a positive result. For example, -1 * -1 = 1."
  [a]
  (PApplet/sq (float a)))

(defn sqrt
  "Calculates the square root of a number. The square root of a number
  is always positive, even though there may be a valid negative
  root. The square root s of number a is such that (= a (* s s)) . It
  is the opposite of squaring."
  [a]
  (PApplet/sqrt (float a)))

;; $$start
;; $$status
